SU1240715A1 - Device for shaping protective tachogram of mine hoist speed limiter - Google Patents

Description

The invention relates to the protection of mine hoisting installations and can be used in the speed limiters of hoisting machines.

The aim of the invention is to simplify the design of the device and increase reliability.

Figure 1 presents the block diagram of the device; 2 shows diagrams for the sake of the device operation.

A device for forming a lock-in and a tachogram of a speed limiter of a shaft hoisting machine comprises a pulse sensor 2 for stirring, kinematically connected with the shaft of the hoist machine 1. At the points of the trunk corresponding to the beginning of the deceleration of one lifting vessel 3 (point A) and another 4 (point B), proximity sensors (5 and 6) for the passage of lifting vessels are installed. A sensor 7 for detecting the direction of movement is connected to the sensor 2. In order to determine the direction of motion, sensor 2 must have at least two sensitive elements. By changing the phase of the output signals of these sensing elements, the node 7 identifies the direction of the vrash, the lifting direction of the lifting device. Figure 1 shows the two outputs of the sensor 2, which corresponds to the presence of two sensitive elements. Node 7 for determining the direction of movement has two exits, on one of which (B) a logical unit appears when the machine is moving in the "Forward" direction, and on the other (H) when moving in the "Backward" direction. A logical structure consisting of AND 8-14 circuits, OR circuit 15 and / 5 flip-flops 16 and 17, controls a reversible counter 18, the counting input 19 of which is connected to a pulse sensor 2, and the reset and stop counters 20 and counting directions 21 are connected to the aforementioned logical structure. The bit outputs of the reversible counter 18 are connected to the inputs of a digital-to-analog converter (D / A converter) 22. The output of the D / A converter is connected to one of the inputs of the subtractor 23, the other input of which is connected to a potentiometer 24 of the maximum controlled speed. The reader is connected to a functional converter 25, the output 26 of which is the output of the device.

The device works as follows.

At the moment when the lifting vessels pass 3 and 4 points of the trunk, corresponding to their deceleration start (points A and B), where the sensors 5 and 6 are installed, the logical signal "1. When passing point A, this signal goes to the connected inputs of circuits AND 10 and 11, and when passing through point B to the inputs of circuits AND 8 and 9. Since the other inputs of these circuits And are connected to the outputs of node 7 for determining the direction of motion, this switches RS-flip-flops

16 and 17 in one or another state. The switching diagrams are shown in Fig. 2, where the output voltages LJi and U2 of the flip-flops and the output voltage Us of the output circuit 5 and 14 are shown. When the machine moves, “Forward (B) signal And | is equal to logical "1 (shaded in the diagram) from the extreme position to the point B of the beginning of the deceleration. When the movement "Back" (H), the signal And equals the logical "1 from the other extreme position to the point A. The signal From equals the logical" 1 in the segment between points A and B, regardless of the direction of movement. This signal is applied to the reset input 20 and stopping the counting of the reversible counter 18, whereby

, the latter is in the zero state and does not react to the pulses arriving at the counting input 19. In the deceleration sections (between the extreme positions and points A and B), logical units appear at the zero outputs / 5-trigger 17 (at

20 when the lifting vessel 3 is in the area from the point A to the left in the end position diagrams) or / 5-flip-flop 16 (when the lifting vessel 4 is in the area between the point B and the right extreme position). In this case, the logical "L" is fed to one of the inputs of the AND circuits connected to the outputs of the movement direction determining unit 7.

When finding lifting vessels in

2Q within one or another deceleration section of the logical "1 at the output of the circuit OR 15 (at the input 2 of the counting direction of the counter 18) appears when the vessels move to the extreme positions. When the movement direction of the lifting vessels

2J (from the extreme positions to points A and B) at the input 21 appears the logical "O. Thus, the counter 18 in the area of motion with a constant speed (between points A and B) is inhibited in the zero state, and in the areas of deceleration it works on addition — when the lifting vessels move to the extreme positions and on subtraction — when they move to the center of the trunk. D / A converter 22 converts the code recorded by counter 18 into an analog signal AND equal to zero in the area between points A and B and linearly increasing as the lifting vessels move from these points to the extreme positions. Subtracter 23 subtracts the signal from the IB constant voltage proportional to the maximum value

Q controlled speed and set by potentiometer 24. The Ib signal at the output of the subtractor 23 has a maximum value when the lifting vessels are located in the trunk section between points A and B and decreases linearly as the latter approach the extreme position.

Functional converter 25 converts a linearly varying Ie signal into a Yiwu signal, a functional relationship

45

which from the position of the lifting vessel relative to the extreme position corresponds to the adopted form of the protective tachogram. For the most commonly used parabolic protection tachogram, the functional transducer 25 is an analog square root extractor.

The diagrams of change of analog signals I4, Io, IB and I as a function of the position of one of the lifting vessels (3) in the barrel are given in Fig.2.

/ TTTTTTI

22

3

i / j

u //////// u

Ui,

5 ff

FIG. 2

Claims (1)

DEVICE FOR FORMING A PROTECTIVE TACHOGRAM OF A SHAFT LIFTING MACHINE SPEED LIMITER, containing a pulse displacement sensor, a direction determination unit, a reversing counter, a digital-to-analog converter, a functional converter, and a maximum controlled speed potentiometer, characterized in that it is equipped with the aim of simplifying and improving reliability in the shaft of the mine with two sensors of passage by the lifting vessels of the points of the beginning of deceleration, with seven two-input circuits And, with two / ^ -triggers, an OR circuit, and a subtracter, and the output of the pulse displacement sensor is connected to the output of the site for determining the direction of movement and the counting input of the reversible counter, the output of the site for determining the direction of movement "Forward" is connected to the first inputs of the first, third, and fifth circuits AND, the output of the unit determining the direction of movement "Back" is connected to the first inputs of the second, fourth and sixth circuits And, the first sensor of passage of the lifting vessel is connected to the second inputs of the first and second circuits And, the second sensor of passage of the lifting the vessel is connected to the second inputs of the third and fourth circuits AND, the outputs of the first and second circuits And are connected to the inputs of the first / iS-trigger, the outputs of the third and fourth circuits And are connected to the inputs of the second / iS-trigger, a single output of the first / iS-trigger is connected to the first input of the seventh circuit And, the zero output of the first / ^ S-trigger is connected to the second input of the sixth circuit And, the single output of the second / iS-trigger is connected to the second input of the seventh circuit And, the zero output of the second / ^ S-trigger is connected to the second input of the fifth circuits AND, outputs of the fifth and sixth circuits And through OR is connected to the input of the counting direction of the reversible counter, the output of the seventh circuit is connected to the reset and stop input of the counting of the reversible counter, the discharge outputs of the reversible counter are connected to the inputs of the digital-analog converter, the output of which is connected to the first input of the subtractor, the second input of the subtractor is connected to the maximum controlled potentiometer speed, and the output is with the input of a functional converter.